For example, in a process for manufacturing an automobile, various constituent elements are welded with respect to the automotive vehicle body. When such welding is performed, clamping of the constituent elements using a clamp apparatus is widely practiced for positioning and fixing the constituent elements in place.
As one type of clamp apparatus, the device disclosed in the specification of German Utility Model Registration No. 29504267 may be cited as an example. More specifically, such a clamp apparatus includes a casing, a cylinder disposed inwardly of the casing, and a clamp arm, which is connected to a rod of the cylinder through a toggle link mechanism. Linear translatory movement of the rod is converted into rotational movement by the toggle link mechanism, and as a result, the clamp arm undergoes swinging movement.
In the clamp apparatus of German Utility Model Registration No. 29504267, as shown in FIGS. 1 and 2 of this publication, a main body of the toggle link mechanism is accommodated in the casing, such that only a connecting shaft is exposed from a side wall of the casing, with a structure being provided in which one end of the clamp arm is connected to a distal end of the exposed connecting shaft. In this case, adhering of so-called spatter (debris), which is generated during welding, onto the main body of the toggle link mechanism can be avoided.
However, in the aforementioned structure in which the connecting shaft of the toggle link mechanism projects from a side surface of the casing, it is difficult for the casing, and hence the widthwise dimension of the clamp apparatus, to be made narrower in width, due to the fact that it is necessary for the connecting shaft to extend along a width direction of the casing.
For this reason, for example, the clamp apparatus cannot be inserted into a narrow clearance. Stated otherwise, a problem occurs in that the locations in which the clamp apparatus can be installed are limited.
For narrowing the widthwise dimension of the casing, as disclosed in German Utility Model Registration No. 9104532, a casing is constituted from a first casing member and a second casing member, in which it is thought to be effective for the clamp arm to project from an opening, which is formed by mating surfaces of the first casing member and the second casing member. In this case, as can be understood from FIG. 1 of this publication, it is not required for a connecting shaft of the toggle link mechanism to extend along the width direction of the casing.